The top U.S. general in Afghanistan says his forces are using their new authorities—which include airstrikes against the Taliban--"almost daily” in support of the Afghan government's efforts to rid the country of insurgents and terrorists.

Speaking at Bagram Air Field on Tuesday, General John "Mick" Nicholson, the commander of U.S. and NATO forces in Afghanistan, said his troops are now better equipped to help Afghan forces take the offensive against the Taliban, and they have begun to carry out their mission in several areas.

Nicholson spoke to reporters accompanying U.S. Defense Secretary Ash Carter, who made an unannounced visit to Afghanistan. In Kabul earlier Tuesday, Carter said the expanded authority that President Barack Obama granted to U.S. forces last month allows "much more efficient use and effective use" of both American and Afghan forces.

U.S. troops in Afghanistan can now attack Taliban fighters directly to gain a strategic advantage. Previously, American forces were only authorized to strike Taliban units if they were under attack or if their Afghan allies were facing imminent defeat.

FILE - Commander of NATO Resolute Support forces and United States forces in Afghanistan, U.S. Army General John Nicholson walks during a change of command ceremony in Resolute Support headquarters in Kabul, Afghanistan, March 2, 2016.

Explaining the new rules of engagement for his troops, Nicholson used the example of last year's lengthy battle for control of Kunduz, in northern Afghanistan. The Taliban launched a complex attack against Kunduz city in late April 2015, and over the course of several months the insurgents made major gains against Afghan forces, while U.S. forces were limited in their ability to join the fight.

Nicholson said U.S. troops were on "a defensive, reactive" footing during the prolonged Taliban offensive.

Kunduz fighting

Only when Taliban forces attacking from three directions gained complete control of Kunduz, five months after their initial attack, were U.S. Army Special Forces able to take an active role in the battle. They made rapid progress in pushing back Taliban fighters and their allies, but that phase of the fighting also was marred by an erroneous American airstrike in early October. A U.S. warplane hunting for a Taliban command center mistakenly bombed a hospital run by Doctors Without Borders, killing dozens of patients and hospital staff.

Now that American forces have more clear-cut guidelines allowing them greater freedom to attack Taliban units, Nicholson said, U.S. assistance has helped Afghan forces expand their control outward from Kunduz city to a large area of that northern province.

Similarly, in southern Afghanistan, the U.S. is attacking Taliban fighters alongside Afghan troops in areas such as Kandahar Province's Maiwand district, the U.S. commander said.

FILE - Afghan security personnel stand alert as they prepare for an operation against Taliban militants in the Aliabad district of Kunduz province, June 12, 2016.

Carter's trip to Afghanistan followed by less than a week Obama's announcement that U.S. troop reductions will be slower than planned in the coming months. Total American forces in Afghanistan as of next January will be 8,400 troops, up from the force of 5,500 men and women originally scheduled to be on duty at the start of 2017.

Troops 'over the horizon'

A senior defense official told VOA several troops will support the NATO mission from regional bases outside Afghanistan.

Nicholson specified that 400 U.S. troops with Resolute Support would be outside Afghanistan.

"Some capabilities we put over the horizon," Nicholson said, "but I'm very comfortable with them being where they are, and we can call them forward [to duty in Afghanistan] if necessary."

The decision to place "some hundreds" of troops outside Afghanistan complicates the question of how many American forces actually are being withdrawn, since any of the units shifted to regional bases could be redeployed into the country on short notice.

Nicholson said about 3,000 troops will be advising Afghan forces as part of NATO’s Resolute Support Mission. Roughly 2,150 of the 8,400 U.S. troops in Afghanistan will support the U.S. counterterrorism mission, dubbed Freedom’s Sentinel, which targets remnants of al-Qaida, pockets of Islamic State fighters and six other terror groups. About 3,300 will serve as enablers for both missions.

WATCH: US forces remain committed in Afghanistan

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